Sandalwood, valued for its heartwood, is a semi-parisitic plant, that is, it requires a host plant to grow. It belongs to the genus Santalum and in total there are 16 species of the plant. Indian sandalwood, Santalum album, grows the fastest and has the greatest percentage of oil in its heartwood (6-7 per cent). IUCN listed Indian sandalwood in its Red List as a "vulnerable' species in 1998 after its production fell by at least 80 per cent over the last 10 years due to overexploitation.